This invention relates generally to a machine for harvesting crops in a field and forming a windrow of cut crop, more particularly, to a specialized header for harvesting specialty crop with an apparatus for transversely conveying the crop material within the header without damaging the crop.
In modern crop harvesting machines, it is desirable to optimize cutting headers for specific crops in order to maximize harvesting efficiency. Such optimized headers are typically based on existing headers with specific-purpose modifications incorporated to alter finite portions of the crop flow within the header to suit the specific crop. This approach helps control production costs of the equipment and extends the life cycle of a basic header design.
One specific application involves harvesting of grasses, seed or other specialty crops having seeds on a stem which must be cut and dried in a windrow a desired amount before undertaking operations to separate the seed from the stems. Care must be taken when working with such crops to minimize disturbances to the cut crop material which results in dislodgement and loss of the seeds. A cutting header must be capable of cutting the crop from the ground and forming a windrow to allow crop drying in advance of subsequent harvesting operations. Conditioning mechanisms are omitted in the harvest of such specialty crops. Experience has shown that other changes to crop moving devices in the header are also necessary to prevent crop clogging and entanglement with the auger. Clogs result in lost harvesting productivity while an operator removes the entangled crop and also lost seed due to the increased disruption to the crop material when the entanglement begins. In many conditions, the tendency of crops to clog results in clumping in the resultant windrow which increases the difficulty of subsequent harvesting operations, such as threshing by a combine. Ground speeds must be reduced, with a resultant decrease in productivity, in order to prevent further loss of seed.
It is known to use a windrower having a header equipped with a transversely arranged auger featuring opposite-hand flighting on each end for conveying severed crop material within the header. U.S. Pat. No. 5,327,709 granted to Webb on Jul. 12, 1994 shows a typical crop severing header using a transverse feed mechanism of this type. It is noted that the auger flighting does not extend into the central section ahead of the crop discharge zone. Instead, smaller paddle structures are provided on the auger drum ahead of the discharge zone to allow the direction of crop flow to be directed rearwardly into the conditioning mechanism. Experience has shown that this same structure delivers unsatisfactory windrowing in the absence of the conditioning mechanism. Replacing the paddle structures with flighting continuing to the center of the auger has also proven unsatisfactory as it causes large clogs of crop material to form in the center of the header resulting in uneven windrows.
It would be desirable to provide a crop transport apparatus for a specialty crop header capable of conveying severed, seed-bearing crop material toward a centrally located discharge zone for formation of a windrow that would overcome the above problems and limitations.